Pressure equalizer



J. A. LUPFER' 2,321,093 PRESSUREEQUALIZ'ER Filed nep. 2o, .1940 2 sheets-$heet 1 June s, '1943.

umile; f

.ull

James A Lupfer. |Nv NToR 'ATTORNEY June 8, 1943. 4. A. LUPI-'ER PRESSURE EQUALIZER Filed Dec. 20. 1940.

2 Sheets-Sheet 2 .lJame Lupfer, TOR

ATTORNEY Patented June 8, 1943 UNITED STATES rareNT ori-ieg PRESSURE EQUALIZER. James A. Lupfer, Tulsa, Okla. pplicaton December 20, 1940, Serial No. 370,953

Y (c1. 13s- 31) 'l' Claims.

This invention relates to pressure equalizers, and more particularly to a liquid pressure equalizervfor use in lpipe lines for reducing pressure variations in the pipe line caused by t'he variable delivery of liquids from a reciprocating pump.

An object of the present invention is to provide a pressure equalizer which will absorb pressure variations in pump 'discharge lines, thereby making it` possible to operate at materially high- -er pressures in such lines and with a greater factor of safety.

Another object of the present invention is to provide a pressure equalizer wherein a plunger is provided which is acted upon by the pressure in theline and' by spring pressure to equalize the line pressures, and which provides novel fea-A tures to avoid excessive friction during the operation of the plunger; to insure a tight seal between the plunger and its cylinder; and means whereby the pressure exerted by the springs on the plunger may be regulated as required.

With'these and other objects in view, as may appear fromthe accompanying specication, the invention consists of various features of construction and combination of parts, which will be first describedin connection with the accompanying-drawings, showing a pressure equalizer of the preferred form embodying the invention, and the features forming the invention will be specificallyv pointed out in the` claims.`

In the drawings: Y

Figure 1 is a vertical section through the improved pressure equalizer.

Figure 2 is a horizontal section through the equalizer taken on the line 2-2 of Figure 1.

Figure 3 is an enlarged detail section taken on the line 3-3 of Figure 1.

Figure 4 is a cross-section taken on the line 4--4 of Figure 1.

Referring more particularly to the drawings, the improved pressure equalizer includes a cylinder, I, the lower end of which isV attached by a suitable attaching ange or collar 2 to the'pipe line (not shown) with which the pressure equalizer is to be associated, and the lower end of the cylinder opens into the pipe line so as to permit the pressure uid flowing through the pipe line to enter the cylinder and engage the lower end of the plunger structure 3. The plunger 3 reciprocates ln the cylinder I and has its upper end connected to a piston 4 which reciprocates in the enlarged portion 5 of the cylinder structure..

A plurality of springs 6 are mounted in the enlarged portion 5 vof theV cylinder structure and engage against theupper side of the-piston 4'and the under side of the cylinder head I for exerting pressure against the piston 4 and consequent--l ly against the plunger 3, ina reverse direction toU the pressure exerted against the-plunger 3 by the pressure fluid acting thereon, Suitable means are provided for regulating the tension of the springs 6 and consequently regulating the pressure exerted by the springs against the piston 4 and plunger 3. This means comprises suitable tensioning discs 3 which engage the ends of the springs remote from the 'piston 4 and -Which threadably receivecap screws 9 carried by thel Thus by adjustment of the cap screwsY head 1. the tension of the springs Iiv may be regulated.k

l v The plunger 3 and piston 4 are connected for limited relative movement to absorbY shocks by means of a stud I0, which is welded or otherwise. f suitably connected or attached to the upperv head II of the plunger and extends slideably through a central opening I2 in the piston 4. A nut I3,is threaded upon the end of the stud projecting above the piston 4 and a spring I4 is positioned' between the nut I3 and the piston 4to permit limited relative movement of the.' piston 4 and plunger 3 and to maintain these members in proper engagement at alltirnes.

equalization of air pressure in the enlarged section 5 of the cylinder and the interior of the plunger 3.

The piston 4 has piston rings I6 carried thereby to provide a relatively tight seal between the piston and the Walls of the enlarged sectionv 5 A of the cylinder structure for the purpose ofjproviding an air cushion for the downwardmove-` ment of the piston 4. The space 20 below the movement of the piston 4 so as to provide the air cushion for the downward movement of the piston.

The plunger V3isof thediferential type, providing an air space` 2| between a part' of the plunger and the inner wall of the cylinder I. This diierential space 2l is connected to 'the vsuctionV of the pump (not shown)` which delivers the pressurevfluid through the pipe `line (not shown) by the connection 22 and to atmosphere,-v through a bleecler valve 23. An air` .chamber l v24 yis also connected with the" differential space The stud VIll is" provided .with a longitudinal -bore I5 to permit y or chamber 2| to prevent creation of an excessive vacuum in this differential space. The line 22 leading to the suction of the pump has a check valve 25 therein so that any leakage passing the piston rings of the plunger is conducted back to the suction line of the pump. This check valve 25 prevents the flow of liquid from the suction of the piunp to the diierential chamber 2| when the pressure in the pump suction is higher than the pressure in the differential chamber. I'he upper end of the plunger 3 is packed, as shown at 26, so as to prevent any leakage past the piston rings 21, which are carried by the plunger, from getting into the enlarged portion 5 of the cylinder.

The lower end of the plunger 3 has its periphery cut away to provide an annular recess for the reception of the piston rings 21. Each piston ring 21 is carried by an individual retainer 28, as clearly shown in Figure 3 of the drawings, and certain vof the piston rings have line pressure, i. e., the pressure of the liquid nowing through the line with which the equalizer is connected, back of them Ato insure'high pressure contact with the cylinder wall- All of the piston rings 21 and their individual retainers 28 are held in place by a coverl plate 29 which-ntsk against the lower end of the plunger 3 and has an annular flange 3|! extending into the pistonring receiving space. The cover plate 29 is yieldably connected to the plunger by means of a setscrewv3| and a spring 32, as clearly shown in Figure l of the drawings, insuring continuous clearance on the side of the pistonrngs. Y W

The lower head 33 of the plunger 3 is provided with a cross passage 34 therein which opens out into suitable ,openings or passages 35 formed in the lowermost vpistonA ring retainer 28. Pressure fluidlfrom the line (not shown) is delivered to the passages 34 and 35 and against the Lback of the lowermost piston ring 21 through asuitable passage 36 formed in the cover plate 129 and the plunger head 33.

An atmospheric Vent 31 opens into the packing 26.

Suitable lubrication ofthe equalizeris provided through a lubricating line 40 and. air is admitted intothe interior ofthe enlarged section 5 of the cylinder'through an air cleaner 4| and an air line 42.

rlhe valve I8 in the bleeder line to the air cushion space 2|! togetherwith the orifice plate I9 permits regulation of the sensitivity of the pressure .equalizer on sudden changesin pressure and the reliefvalve or check valve 23 is provided in the line 22 which communicates with the suction of the pump to relieve any liquidfin the diierential chamber 2| should the check valve 25 become inoperative. Y y

The stud I0 and its manner of establishing connection between'the plunger 3 and the piston 4, as heretofore described, will allow for slight variations in thecylinder walls and the walls of the enlarged section 5 of the cylinder structure without excessive friction and in effect allows the piston. 4 to float y freely, independentlyy of the plunger 3, which is acted upon by the pressure liquid in the line.

It `will be understood that the invention is not tor be limited to the specific construction or arrangement of parts shown, but that they may 'bewidelyj modified within the invention defined by bheblaimsw 1. In a pressure equalizer, a cylinder, a plunger in said cylinder and adapted to be acted upon by the liquid the pressure of which is to be equalized, a spring pressed piston connected to said plunger, springs acting on said piston in opposition to liquid pressure against said plunger, yieldable means connecting said plunger and piston to provide connected movement of the 101813011 and plunger in either direction and allow limited relative movement of the plunger and piston, means for regulating the tension of said springs to regulate the pressure opposing pressure exerted on said plunger, said piston moving in said cylinder and arranged to provide an air space in opposition to the action of said springs, and means controlling the air in said space to provide a regulatable air cushion for the piston.

2. In a pressure equalizer, a cylinder, a plunger in said cylinder and adapted to be acted upon by the liquid the pressure of which is to be equalized, a spring pressed piston connected to said plunger, springsV acting on said piston in opposition to liquid pressure -against said plunger, yieldable means connecting said plunger and piston to allow limited relative movement of the plunger and piston, means for regulating the tension of said springs to regulate the pressure opposing. pressure exerted on said plunger, said pistonV moving in said cylinder and'arranged to provide an air space in opposition to the action of said springs, means controlling the air in said space to provide a regulatable air cushion for the piston, said plunger being providedwith opposed diiier` ential areas one of which is subject to pressure lower than the liquid pressure acting upon the other area.

3. In 'a pressure equalizer, a cylinder, a plung er in said cylinder and adapted to be acted upon by the liquid the pressureV of which is to be equal#4 ized, a spring pressed piston connected to saidf plunger, springs acting on said piston in opposition to liquid pressure' against said plunger, said plunger comprising a body shell and a cover plate engagedfby the pressure liquid, means yieldably `connecting said cover plate to saidshell, said shell having a diierential area thereon opposed to said cover plate, means for subjecting vsaid diierential area to air pressure, and a safety valve connectedw to the differential chamber formed by said differential area between the shell and cylinder to permit the escape of fluid fromthe differential chamber whenpressure thereinA rises above a predetermined degree. Y

4. In a pressure equalizer, a cylinder, a plung-k er in said cylinder and adapted to be acted upon Y of which is to be equalized, a spring pressed piston connected to `said by the liquid the pressure plunger, springs acting on said piston in opposition to liquid pressure against said plunger, said plunger having opposed differential areas oneof which. is subjected to pressure lower than the liq uid pressure acting upon the other area, a connection to the differential chamber formed bysaid diierential area between the plunger and cylinder and adapted to be connected to the suc j tion of la pump the dischargev liquid pressure of which acts uponv thepplunger, and a check `valve in saidconnection whereby when the pressure in said differential chamber exceeds the suction rpressure of `the pump the pump will drain saidchamber. Y Y f 5. In a pressure equalizer, a cylinder, a plunger in said cylinder, said plunger having opposed differential areas one of l pressure of fluid the equalized, said cylinder and plunger constructed which is subjected vto pressure of which is to' be and arranged to provide an air chamber facing the other of said diierential areas, said air chamber open to atmosphere, yieldable sealing means carried by said plunger and acted upon by pressure of the uid whose pressure is to be equalized to prevent leakage of fluid into said air chamber, and a safety valve connected to said air chamber to permit escape of air from the air chamber when pressure therein rises above a predetermined degree.

6. In a pressure equalizer, a cylinder, a plunger in said cylinder and adapted to be acted upon by the fluid the pressure of which is to be equalized, a spring-pressed piston connected to said plunger, springs acting upon said piston in opposition to liquid pressure against the plunger, said piston and cylinder constructed and arranged to provide an air space in opposition to the action of said springs, said plunger having opposed differential areas one of which is subjected to pressure of fluid the pressure of which is to be equalized, said cylinder and plunger constructed and arranged to provide an air chamber facing the other of said differential areas, said chamber open to atmosphere whereby said other differential area will be subjected to atmospheric pressure, and means for controlling the air in said air space to permit regulation of the air cushion for the piston proportionate to the differential of the pressures acting upon the difierential areas of the plunger.

7. In a pressure equalizer, a cylinder, a plunger in said cylinder and adapted to be acted upon by the iiuid the pressure of which is to be equalized, a spring-pressed piston connected to said plunger, springs acting upon said piston in opposition to liquid pressure against the plunger, said piston and cylinder constructed and arranged to provide an air space in opposition to the action of said springs, said plunger having opposed differential areas one of which is subjected to pressure of fluid the pressure of which is to be equalized, said cylinder and plunger constructed and arranged to provide an air chamber facing the other of said differential areas, said chamber open to atmosphere whereby said other diierential area will be subjected to atmospheric pressure, means for controlling the air in said air space to permit regulation of the air cushion for the piston proportionate to the differential of the pressures acting upon the diierential areas of the plunger, and yieldable sealing means carried by said plunger and acted upon by pressure of the uid whose pressure is to be equalized to prevent leakage of fluid into said air chamber.

JAMES A. LUPFER. 

